<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>外边距</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border:1px solid red;
        }
        #d1{
            margin-top: 20px;
            margin-left: 50px;
            margin-bottom: 50px;
            /*4个方向赋值*/
            margin:50px;
            /*上下和左右赋值*/
            margin: 50px 100px;
            /*上右下左赋值*/
            margin: 10px 20px 30px 40px;
        }
        #d2{
            /*上下相邻两个元素彼此添加外边距取最大值*/
            margin-top: 50px;
        }
        #s1{
            /*行内元素上下边距无效*/
            margin-right: 50px;
        }
        #s2{
            margin-left: 30px;
        }
    </style>
</head>
<body>
    <div id="d1">div1</div>
    <div id="d2">div2</div>
    <span id="s1">span1</span>
    <span id="s2">span1</span>
</body>
</html>